Re: builtin sscanf

[Jeff Law <law at redhat dot com>]

On 10/13/2016 01:03 AM, fedor_qd@mail.ru wrote:
> Are GCC builtin function sscanf, strtod and atof independent from libc provided by os?
> Always yours, Fiodar Stryzniou
They are largely independent -- though GCC has knowledge of the 
requirements imposed by POSIX and assumes those requirements except in a 
freestanding implementation.

GCC sometimes has small amounts of knowledge of the implementation. For 
example, it knows about how the implmementation handles certain 
formatting which vary across implemetations (%p for example).  That 
knowledge is used to give more precise buffer overflow warnings and can 
be used to optimize return values from certain *printf calls.

Jeff